Improve Lua console behaviour (daid#2145)

- Print input lines prepended with '> ' before running them.
- Store history to allow easily returning to previous inputs.

src/gui/gui2_textentry.cpp

@@ -182,6 +182,11 @@ void GuiTextEntry::onTextInput(sp::TextInputEvent e)
         break;
     case sp::TextInputEvent::Up:
     case sp::TextInputEvent::UpWithSelection:{
+        if (up_func)
+        {
+            up_func(text);
+            return;
+        }
         int end_of_line = text.substr(0, selection_end).rfind("\n");
         if (end_of_line < 0)
             return;
@@ -194,6 +199,11 @@ void GuiTextEntry::onTextInput(sp::TextInputEvent e)
         }break;
     case sp::TextInputEvent::Down:
     case sp::TextInputEvent::DownWithSelection:{
+        if (down_func)
+        {
+            down_func(text);
+            return;
+        }
         int start_of_current_line = text.substr(0, selection_end).rfind("\n") + 1;
         int end_of_current_line = text.find("\n", selection_end);
         if (end_of_current_line < 0)
@@ -448,6 +458,17 @@ GuiTextEntry* GuiTextEntry::validator(Validator v)
     return this;
 }
 
+GuiTextEntry* GuiTextEntry::upCallback(func_t func)
+{
+    this->up_func = func;
+    return this;
+}
+GuiTextEntry* GuiTextEntry::downCallback(func_t func)
+{
+    this->down_func = func;
+    return this;
+}
+
 void GuiTextEntry::setCursorPosition(int offset)
 {
     selection_start = selection_end = std::clamp(offset, 0, int(text.size()));

src/gui/gui2_textentry.h

@@ -29,6 +29,8 @@ class GuiTextEntry : public GuiElement
     const GuiThemeStyle* back_style;
     func_t func {nullptr};
     func_t enter_func {nullptr};
+    func_t up_func {nullptr};
+    func_t down_func {nullptr};
 
     const float blink_rate = 0.530f;
     sp::SystemTimer blink_timer;
@@ -59,6 +61,8 @@ class GuiTextEntry : public GuiElement
     GuiTextEntry* callback(func_t func);
     GuiTextEntry* enterCallback(func_t func);
     GuiTextEntry* validator(Validator func);
+    GuiTextEntry* upCallback(func_t func);
+    GuiTextEntry* downCallback(func_t func);
 
     void setCursorPosition(int offset);
 protected:

src/menus/luaConsole.cpp

@@ -41,7 +41,22 @@ LuaConsole::LuaConsole()
     entry->enterCallback([this](string s) {
         P<ScriptObject> script = engine->getObject("scenario");
         if (script)
+        {
+            LuaConsole::addLog("> " + s);
             script->runCode(s);
+            history.append(s);
+            entry->setText("");
+        }
+    });
+    entry->upCallback([this](string s) {
+        string text = history.movePrevious(s);
+        entry->setText(text);
+        entry->setCursorPosition(text.size());
+    });
+    entry->downCallback([this](string s) {
+        string text = history.moveNext(s);
+        entry->setText(text);
+        entry->setCursorPosition(text.size());
     });
 
     top->hide();
@@ -102,3 +117,42 @@ void LuaConsole::update(float delta)
         }
     }
 }
+
+string ConsoleHistory::movePrevious(string s) {
+    if (position == 0)
+        // beginning of history, nothing to go up to. keep the line the same.
+        return s;
+
+    if (position == entries.size())
+        // previous from a line not in history; set it pending so we can go back down to it later
+        pending = s;
+    else
+        entries[position] = s;
+
+    return entries[--position];
+}
+
+string ConsoleHistory::moveNext(string s) {
+    if (position == entries.size())
+        return s;
+
+    if (position + 1 == entries.size())
+    {
+        // end of history, nothing to do down to.
+        // if we had a pending entry, put it back
+        position++;
+        string wasPending = pending;
+        pending = "";
+        return wasPending;
+    }
+
+    entries[position] = s;
+    return entries[++position];
+}
+
+void ConsoleHistory::append(string s)
+{
+    entries.push_back(s);
+    position = entries.size();
+    pending = "";
+}

src/menus/luaConsole.h

@@ -6,6 +6,19 @@
 #include "timer.h"
 
 
+class ConsoleHistory
+{
+public:
+    string movePrevious(string);
+    string moveNext(string);
+    void append(string);
+
+private:
+    std::vector<string> entries;
+    unsigned int position = 0;
+    string pending = "";
+};
+
 class GuiTextEntry;
 class LuaConsole : public GuiCanvas, public Updatable
 {
@@ -17,6 +30,7 @@ class LuaConsole : public GuiCanvas, public Updatable
     void update(float delta) override;
 private:
     std::vector<string> log_messages;
+    ConsoleHistory history;
     GuiElement* top;
     GuiTextEntry* log;
     GuiTextEntry* entry;